Wheels Make the World Go Round: Simple Machines for Kids by Andi Diehn, If you had to design a wheelbarrow, how would you do it? How would you make it move easily when pushing it? Skis? Stilts? Springs? How about wheels? Learn how wheels work along with axles and how they use mechanical advantage to make moving heavy objects from place to place. Also, learn other ways wheels are used besides transportation. An Introductory poem offers language arts connections while a hands-on activity at the end reinforces concepts in the book. A glossary and photos offer additional supplemental learning opportunities. Paperback, 32 pages. Recommended for ages to 8 years old.